How to make 2 threads run for a certain amount of time

[forevermirin]

Use cond_wait and cond_signal (along with a mutex)
c++ - understanding of pthread_cond_wait() and pthread_cond_signal() - Stack Overflow

Your two threads need to take a void* parameter as well.

They should also return NULL if there is nothing to report at the end.

Thanks for your answer.
I took a look at the link you provided, but how do I implement this for my program?